COMPARISON BETWEEN THE SCINTIGRAPHIC UPTAKE AND PLASMA CLEARANCE OF 99mTc-DIETHYLENETRIAMINEPENTACETIC ACID (DTPA) FOR THE EVALUATION OF THE GLOMERULAR FILTRATION RATE IN DOGS

The scintigraphically measured percentage dose uptake of ^99mTc-DTPA by the kidneys and the plasma clearance of ^99mTc-DTPA have been reported to correlate well with inulin clearance. These two parameters were evaluated in seven dogs with known or suspected naturally occurring renal disease and compared to simultaneously measured renal inulin clearance. Correlation between inulin clearance and the ^99mTc-DTPA plasma clearance was better ( p =.0016) than the correlation between the percentage DTPA uptake by the kidney. It was concluded that measurement of ^99mTc-DTPA plasma clearance is a more accurate method to estimate global glomerular filtration rate (GFR) than the percentage kidney uptake.     

Localization of Oestrogen Receptors in the Epididymis During Sexual Maturation of the Domestic Cat

Oestrogens are involved in regulation of spermatogenesis and sperm maturation and are essential for male fertility. To study the role of oestrogens on epididymal function in the domestic cat, we analyzed the localization patterns of oestrogen receptors (ERs) within the epididymis of juvenile, pubertal and adults using immunohistochemistry. Cat epididymal tissues obtained during routine castrations were fixed in chilled Bouin's solution and processed for immunohistochemistry with ER-specific antibodies. For a certain receptor type, ER localization was influenced by donor age. In the juvenile epididymis, ERα was localized in the nuclei of epithelial cells of efferent ducts and undifferentiated epithelium of the ductus epididymis. During puberty, ERα localization in the undifferentiated epithelium of the epididymis shifted from the nuclei to the cytoplasm and plasma membrane. Oestrogen receptor-α level was highest in the pubertal and adult epididymis, especially within the cytoplasm and in plasma membranes of caput epithelial cells. This finding was suggestive of a role in fluid reabsorption within the efferent ducts and the epididymis. In corpus and cauda regions, ERα was less abundant, suggesting a minor role for oestrogens in sperm storage areas. Interestingly, localization of ERβ was neither influenced by age nor location within the epididymis and was ubiquitous throughout. Results demonstrate that oestrogen actions within the epididymis may be predominantly mediated through ERα during sexual maturation in the domestic cat.     

Growth and feed utilization by yearling horses fed added dietary fat

Twenty-four yearlings were used to evaluate the efficacy of feeding feed-grade fat to growing horses. All horses were started on trial at 13-months-of-age and were fed for 112 days. The experimental diets, containing similar nutrient-to-calorie ratios, were: 1) control (no added fat; 2) 5% added fat and; 3) 10% added fat. There was a trend for yearlings fed the 10% added fat diet to grow faster and eat less feed than those on the control diet. Data from this study indicate that feed-grade fat can be safely fed to growing horses. Feeding fat to yearlings stimulated growth and efficiency of feed utilization initially, but these effects were not maintained as the yearlings grew toward maturity.     

A comparison of epidural buprenorphine with epidural morphine for postoperative analgesia following stifle surgery in dogs

Objective To compare the efficacy of epidural buprenorphine with epidural morphine for post‐operative pain relief in dogs undergoing cranial cruciate ligament rupture repair. Study design A randomized, double blind clinical trial. Animals Twenty client‐owned dogs with cranial cruciate ligament rupture. Methods Dogs were randomly assigned to receive either epidural buprenorphine (4 µg kg^?1) or epidural morphine (0.1 mg kg^?1) in a total volume of 0.2 mL kg^?1. Epidural injections were performed immediately after induction of anesthesia. End‐tidal halothane and CO₂ were recorded every 15 minutes from the time of epidural administration of drug to extubation. A numerical rating pain score system was used by a blinded observer to evaluate analgesia beginning at extubation and continuing at specific intervals for 24 hours after surgery. Heart rate, respiratory rate, and blood pressure were recorded noninvasively at the same times. If pain score indicated moderate discomfort, rescue morphine at 1.0 mg kg^?1 was administered intramuscularly. Results There were no significant differences between groups with respect to pain score, heart rate, respiratory rate, indirect blood pressure, end‐tidal halothane or end‐tidal CO₂ at any time point. Fifty percent of dogs in the buprenorphine group and 50% of dogs in the morphine group required rescue analgesic medication. Time of systemic rescue morphine administration did not differ significantly between the two groups. There were no clinically observable side‐effects from epidural administration of either drug in any of the dogs of this study. Conclusions Epidural buprenorphine is as effective as epidural morphine for the relief of postoperative hindlimb orthopedic pain in dogs. Clinical relevance Buprenorphine appears to be an effective opioid for epidural use in healthy dogs. Buprenorphine may offer certain advantages over morphine for epidural use, such as lower abuse potential and, in some clinics, reduced cost and less wastage of drug.     

THE EFFECTS OF INTRA-ARTICULAR ANESTHESIA ON SOFT TISSUE-AND BONE-PHASE SCINTIGRAPHY IN THE HORSE

Soft tissue- and bone-phase scintigrams were acquired from 4 normal horses before and over a 14-day period after metacarpophalangeal, antebrachiocarpal, tarsocrural and tarsometatarsal joint blocks. Images were evaluated subjectively and quantitatively for increased activity in these regions. The antebrachiocarpal block resulted in obvious focal accumulation of activity on soft tissue-phase scintigrams. This increased activity was greatest 2 to 4 days postanesthesia and persisted up to 14 days postanesthesia. On quantitative analysis of soft tissue-phase images, similar trends were noted after the metacarpophalangeal and tarsocrural blocks, but these increases were relatively mild and were not evident on subjective evaluation of the images. Abnormal soft tissue-phase activity was not associated with the tarsometatarsal block. On bone-phase scintigrams, increased activity was not present following any of these joint blocks.     

The Effect of Sedation on Gastric Emptying of a Liquid Marker in Ponies

OBJECTIVE: The effect of sedation on gastric emptying was evaluated in six ponies by monitoring serum concentrations of acetaminophen (AP) after intragastric administration. EXPERIMENTAL DESIGN: Prospective randomized experimental study. ANIMALS: Six adult ponies, 135 to 275 kg. METHODS: Fifteen minutes after the intravenous administration of xylazine (1 mg/kg), butorphanol (0.05 mg/kg), acepromazine (0.05 mg/kg) or saline, ponies were given AP (20 mg/kg in 350 mL water) by stomach tube. Blood for AP analysis was collected at baseline and 15, 30, 45, 75, 90, 105, and 120 minutes after AP administration. The time (Tmax) to reach peak serum concentration (Cmax), and the area under the AP serum concentration versus time curve (AUC) were determined for each treatment group. RESULTS: Tmax was 31 mins in the control group, and this increased significantly (P<.05) after sedation. Cmax decreased (P<.05) after xylazine administration, and AUC decreased (P<.05) after acepromazine. CONCLUSIONS: This study indicated that sedation has a significant effect on the gastric emptying rate of a liquid in ponies.     

Mechanical Testing and Evaluation of Eight Synthetic Casting Materials

Eight synthetic casting materials were evaluated with respect to tensile and fatigue strengths, exothermicity (evolution of heat during polymerization), permeability (porosity), radiolucency, and cost. Strength determination for a five-layer sample included measurement of the ultimate load at which a material failed, the ability to absorb energy, and the stiffness a material possessed after application of a cyclic stress. Results indicated that Vet Cast was superior with respect to tensile and fatigue strengths. The exothermic reaction associated with the "curing" or polymerization process was evaluated and not considered excessive although Ultra Cast attained a temperature of 48.0°C and was uncomfortable to handle during application. Permeability was determined. Delta Lite and Hexcelite NS were the most permeable materials and dried more rapidly and thoroughly after immersion than the other casting materials. Hexcelite NS was considered the least radiolucent material and was the most expensive material studied. Each of the synthetic casting materials demonstrated superiority in one or more of the categories tested. No one product demonstrated consistent superiority in criteria appropriate for clinical application.